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3 years ago

I NEED HELP ASAP! :)

Chemistry

1 answer:

cluponka [151]3 years ago

7 0

Answer:

When adding the measurements 42.1014g + 190.5g, the answer has seven significant figures.

When dividing the measurements 400g/32.2 cm^3, the answer has ten significant figures.

Explanation:

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How many grams of precipitate will be formed when 20.5 mL of 0.800 M

Anton [14]

Answer:

There will be formed 1.84 grams of precipitate (NaNO3)

Explanation:

Step 1: The balanced equation

CO(NO3)2 (aq) + 2 NaOH (aq) → CO(OH)2 (s) + 2 NaNO3 (aq)

Step 2: Data given

Volume of 0.800 M CO(NO3)2 = 20.5 mL = 0.0205 L

Volume of 0.800 M NaOH = 27.0 mL = 0.027 L

Molar mass of NaNO3 = 84.99 g/mol

Step 3: Calculate moles of CO(NO3)2

Moles CO(NO3)2 = Molarity * volume

Moles CO(NO3)2 = 0.800 M * 0.0205

Moles CO(NO3)2 = 0.0164 moles

Step 4: Calculate moles NaOH

moles of NaOH = 0.800 M * 0.027 L

moles NaOH = 0.0216 moles

Step 5: Calculate limiting reactant

For 1 mole CO(NO3)2 consumed, we need 2 moles of NaOH to produce 1 mole of CO(OH)2 and 2 moles of NaNO3

NaOH is the limiting reactant. It will completely be consumed.

CO(NO3)2 is in excess. There willbe 0.0216 / 2 = 0.0108 moles of CO(NO3)2 consumed. There will remain 0.0164 - 0.0108 = 0.0056 moles of CO(OH)2

Step 6: Calculate moles of NaNO3

For 2 moles of NaOH consumed, we have 2 moles of NaNO3

For 0.0216 moles of NaOH, we have 0.0216 moles of NaNO3

Step 7: Calculate mass of NaNO3

mass of NaNO3 = moles of NaNO3 * Molar mass of NaNO3

mass of NaNO3 = 0.0216 moles * 84.99 g/mol = 1.84 grams

There will be formed 1.84 grams of precipitate (NaNO3)

5 0

3 years ago

What is the SI base unit for time?

MaRussiya [10]

The "second" is the SI base unit of time.

6 0

3 years ago

2.(04.01 LC)

Mila [183]

Answer:

2KClO3 —> 2KCl + 3O2

The coefficients are 2, 2, 3

Explanation:

From the question given above, we obtained the following equation:

KClO3 —> 2KCl + 3O2

The above equation can be balance as follow:

There are 2 atoms of K on the right side and 1 atom on the left side. It can be balance by putting 2 in front of KClO3 as shown below:

2KClO3 —> 2KCl + 3O2

Now, the equation is balanced.

Thus, the coefficients are 2, 2, 3

8 0

3 years ago

How many particles are in 23 g of H 2 O?

Sedaia [141]

1 mole of any substance contains 6.022 × 1023 particles.

⚛ 6.022 × 1023 is known as the Avogadro Number or Avogadro Constant and is given the symbol NA

N = n × NA

· N = number of particles in the substance

· n = amount of substance in moles (mol)

· NA = Avogardro Number = 6.022 × 10^23 particles mol-1

For H2O we have:

2 H at 1.0 each = 2.0 amu
1 O at 16.0 each = 16.0 amu
Total for H2O = 18.0 amu, or grams/mole

It takes 18 grams of H2O to obtain 1 mole, or 6.02 x 1023 molecules of water. Think about that before we answer the question. We have 25.0 grams of water, so we have more than one mole of water molecules. To find the exact number, divide the available mass (25.0g) by the molar mass (18.0g/mole). Watch how the units work out. The grams cancel and moles moves to the top, leaving moles of water. [g/(g/mole) = moles].

Here we have 25.0 g/(18.0g/mole) = 1.39 moles water (3 sig figs).

Multiply 1.39 moles times the definition of a mole to arrive at the actual number of water molecules:

1.39 (moles water) * 6.02 x 1023 molecules water/(mole water) = 8.36 x 1023 molecules water.

That's slightly above Avogadro's number, which is what we expected. Keeping the units in the calculations is annoying, I know, but it helps guide the operations and if you wind up with the unit desired, there is a good chance you've done the problem correctly.

N = n × (6.022 × 10^23)

1 grams H2O is equal to 0.055508435061792 mol.

Then 23 g of H2O is 1.2767 mol

To calculate the number of particles, N, in a substance:

N = n × NA

N = 1.2767 × (6.022 × 10^23)

N= 176.26

N=

3 0

2 years ago

Which of the following is a synthetic organic material?

Rudik [331]

The answer is: Plastic
Plastic is the result of the addition polymerization of poly(alkenes). Thus plastic is a synthetic organic material.

Hope it helped!

4 0

3 years ago

Read 2 more answers